Burst in Your Mouth

The bubble burst in 2003. In July of that year, during the filming of Decoding Ferran Adrià, El Bulli’s notorious chef served host Anthony Bourdain green pea “ravioli.” They were bubbles made from pea purée that burst in Bourdain’s mouth. Meanwhile, Adrià’s brother and pastry chef, Albert Adrià, made them in front of a stunned food-industry crowd but did not give away the secret of how these otherworldly ravioli were made.

Now we know that the ingredients used to make them were sodium alginate and calcium chloride. Sodium alginate, a powerful algae-based thickener, is often used in pie filling. And calcium chloride, a kind of salt, is commonly used in cheese making. Together they react to form a firm yet delicate gelatin. The red stuffing in some olives is probably not julienned pimiento but strips of pepper purée solidified with sodium alginate and calcium chloride.

Ferran Adrià was the first to use these two industrial ingredients in an upscale restaurant to make what’s now the latest rage in modern dining: spheres, or bubbles—also known as “ravioli.” He and his creative team at El Bulli Taller, the restaurant’s off-season workshop run by his brother, discovered that if they removed drops of food mixed with sodium alginate from a calcium chloride bath at just the right moment, they would get liquid-filled spheres.

Previously, you could always buy sodium alginate, calcium chloride, and other industrial additives from Asian vendors such as Qingdao Zhouji Chemical Industry Co., but only in 50-pound sacks. Now that these ingredients are at the core of the molecular gastronomy trend, new dealers have popped up selling more manageable quantities.

Scoring the Chemicals

El Bulli introduced its line, Texturas, in the United States last June. They now offer 16 ingredients and one set of special tools. Each ingredient and tool canister is packaged with a basic recipe booklet, and more recipes can be found on the company’s website. Texturas is also available from Koerner and La Tienda.

Willpowder, marketed by El Bulli protégé Chef Will Goldfarb of New York City’s Room 4 Dessert, offers smaller quantities of some of the same compounds.

We tested both lines to make spheres. From Texturas, we used Algin and Calcic—the company’s brand names for sodium alginate and calcium chloride—as well as their special spherification tools called Eines (Catalan for “tools.”) We tested the same additives from Willpowder.

Texturas’s prices are high, but these powders will last a long time. Canisters contain 300 to 600 grams of powder, and you’ll use only a gram or two at a time. Willpowder is priced higher per ounce but sells in smaller quantities, so overall prices are lower. It also comes in handy resealable packs.

Along with the chemical additives, I used Texturas’s set of measuring spoons, two large plastic syringes, and two “Collecting Spoons”—perforated metal spoons for retrieving spheres.

When testing both brands, I followed the recipe for Spherical Tea Ravioli on the Texturas website, which called for 1.5 grams of Algin (sodium alginate) and 400 grams of tea. First I poured 75 grams of water into a bowl, then added the Algin. Sodium alginate has a faint scent of rubber—like the first huff of a new Barbie doll—but ideally it should be rendered almost completely undetectable by the taste of your food.

I mixed the ingredients well with a hand blender, trying to minimize bubbles by keeping the blades immersed, as bubbles will cloud the spheres. (It’s just an aesthetic preference; they don’t ruin the spheres.) The sodium alginate immediately thickened the water to goo. Some of the mixture stuck to the head of my blender, and I carefully scraped it back in with my finger, then re-blended. It turned somewhat cloudy. Next I added Earl Grey tea and blended again to mix. I set it aside for about an hour to let the bubbles dissipate and the alginate fully hydrate to its full effectiveness. After resting, the mixture became clear with a thin layer of bubbles on top. It had the viscous consistency of unset Jell-O.

In the meantime, I made the calcium chloride bath by stirring 3.2 grams of Calcic (calcium chloride) into 500 grams of water. It dissolved quickly and easily.

Next, the Syringe

Once the tea mixture had rested, I tried making little spheres the size of caviar. Using one of the plastic syringes, I sucked up some of the tea mixture and dropped it into the Calcic bath. The first attempts to make little spheres may come out long and wormy until you get the feel of it.

To make spheres the size of egg yolks, I filled the measuring teaspoon with the tea mixture and tipped it into the Calcic bath with a single, smooth turn of the wrist. I let the sphere set for about 30 seconds, and then carefully lifted it out with a Collecting Spoon.

I transferred the caviar and larger spheres to a plain water bath to rinse off the excess Calcic. After lifting them out with the second Collecting Spoon, I served them immediately at room temperature. They popped in the mouth refreshingly, bursting with tea, leaving a light membrane that melted quickly, all tasting just like a subtler version of the original tea with no discernable chemical taste. The results with the Willpowder products were the same as with the Texturas products, feeling and tasting nearly identical.

You can vary the thickness of the membrane by leaving the spheres in the Calcic bath for longer periods of time. Just remember that after they are taken out, they will continue to set through, becoming more jelly-like, even after they are rinsed in water. For maximum bursting effect they should be served immediately, but they can be chilled or warmed for a few minutes in liquid, first. Also, it’s harder to make spheres with foods that have high acidity and/or calcium levels. So stay away from ingredients like lemonade and milk in the beginning.

Just Wing It

Though you typically wouldn’t rely on a manufacturer to provide recipes, in this case detailed instructions are needed. There are no written recipes for how to cook with these chemical additives, aside from the latest El Bulli books, which are not yet available in the United States and are not in English. Both Texturas and Willpowder do provide some recipes with basic proportions of ingredients on their websites, but neither offers instructions on how to form spheres. I had my own experience cooking at El Bulli to draw from, but for others the lack of detailed info could be a problem. There is a somewhat helpful thread on eGullet discussing spherification. If you can make it to Barcelona, Solé Graells, an ingredients and materials distributor, offers the only course currently on Texturas. It’s free but taught in Catalan; English translation is available upon request.

I’ll bet you’ll soon see easy kits containing smaller quantities of these additives, precise recipes, and great Web support. But how much cooler would it be to say you were making spheres back when the only real instructions available were in Catalan?